#include <iostream>
#include <pthread.h>
#define PI 3.1415926
using std::cout;
using std::endl;

class Circle
{
public:
    Circle()
        :_radius(0)
    {
        cout<<"Circle()"<<endl;
    }

    Circle( double radius)
        :_radius(radius)        
    {
        cout<<"Circle(double)"<<endl;
    }

    double getArea(){
        return PI*_radius*_radius;
    } 

    double getPerimeter(){
        return 2*PI*_radius;
    }

    void show(){
        cout<<"-------------------------------"<<endl;
        cout<<"the circle's Radius:"<<_radius<<endl;
        cout<<"the circle's Perimeter:"<<getPerimeter()<<endl;
        cout<<"the circle's Area:"<<getArea()<<endl;
        cout<<"-------------------------------"<<endl;
    }

private:
    double _radius;
};

void test(){
Circle c(3.0);
c.show();
}

int main()
{


    test ();
    return 0;
}

